Opposition leader Raffi Hovannisian on Friday acknowledged differences among his Zharangutyun (Heritage) party and two other major parties challenging President Serzh Sarkisian and set conditions for their continued joint activities.

Hovannisian said that Zharangutyun, Gagik Tsarukian’s Prosperous Armenia Party (BHK) and Levon Ter-Petrosian’s Armenian National Congress (HAK) still lack a common “full agenda” despite a series of anti-government rallies held in recent months. He said the opposition trio should clarify its objectives if it is to make any further progress in its campaign for “regime change.”

“The key points of that agreement [proposed by Zharangutyun] is that the aim of the opposition movement is free, independent and constitutional Armenia, and that the principal means of attaining that goal is an immediate, complete and systemic regime change through pre-term parliamentary and presidential elections,” Hovannisian told the press.

The Zharangutyun leader also demanded that the three parties make key decisions “only by consensus.” “We believe in the movement but the moment of truth has come,” he said. “I am calling for us to reach an agreement on principles and further actions in an open, public and accountable manner … I hope that by the end of November we will have a joint proposal to the people of Armenia.”

The appeal seemed primarily addressed to the BHK, the largest and most influential of the three parties. Unlike Zharangutyun and the HAK, Tsarukian’s party has been careful not to demand Sarkisian’s resignation. BHK leaders have indicated that they would settle for government concessions relating to the conduct of the next parliamentary elections.

The BHK also seems reluctant to hold more anti-government rallies in Yerevan in the coming weeks and months. This stance prompted a public rebuke from the HAK earlier this month.

It was announced earlier this week that the opposition trio will again rally supporters in the capital on December 10. The demonstration is unlikely to be followed by sustained street protests, however.

With Hovannisian refusing to answer questions from journalists, it was not clear whether Zharangutyun will keep cooperating with the HAK and the BHK if its proposals are rejected. The Zharangutyun leader said only that his party will organize separate rallies in Yerevan, Gyumri and Vanadzor on December 5-6.